1. Field of the Invention
The present invention relates to a method and an apparatus for reducing standby power of a portable terminal. More particularly, the present invention relates to a method and an apparatus for reducing standby power of a portable terminal in which a paging interval is synchronized with a Subscriber Identification Module (SIM) card polling interval when the portable terminal enters into a sleep mode such that SIM card polling and paging channel monitoring are performed at the same time.
2. Description of the Related Art
Due to the rapid adoption of a portable terminal, the portable terminal has become ubiquitous in modern life. With the introduction of the smartphone variety of the portable terminal, the portable terminal can now provide not only a voice call service but also various data transmission services and additional services, thereby additionally serving as a multimedia communication device. Various methods are used to increase battery use time in accordance with the use of the portable terminal as a multimedia communication device.
When using the portable terminal, a typical state of the portable terminal a user encounters is an idle state of the portable terminal. Thus, the battery use time may be effectively increased by reducing standby power of the portable terminal. In particular, maintaining a sleep mode during the idle state is most effective.
Subscriber Identification Module (SIM) card polling, which identifies whether a SIM card is inserted, and paging channel monitoring, which monitors whether a paging channel is received, are performed when the portable terminal wakes up from the sleep mode. Therefore, the battery use time may be effectively increased by controlling a SIM card polling interval and a paging channel monitoring interval in the sleep mode of the portable terminal. However, in the technology of the related art, a frequency of the SIM card polling is controlled according to a service state of the portable terminal, which does not significantly reduce total current consumption.
Therefore, a need exists for a technique for reducing standby power of a portable terminal in a sleep mode that takes into consideration a paging interval and a SIM card polling interval.